How to make Msvc++ express 2010 application compatible to 64bit machines?-Collection of common programming errors

32-bit applications will work on Win64 OS’s.

There are some special things you might need to do if your application needs to access the ‘true’ system32 directory or certain registry keys. However, the vast majority of 32-bit applications don’t need to deal with that (some that might include file managers or registry editors). In fact, the redirection was specifically put in place by Microsoft so that the redirections would help the application compatibility.

However, if your application requires a special device driver – that would have to be built for a 64-bit platform (again, this is pretty rare).

You should test your application on a 64-bit platform, but the expectation is that in general it should just work.